Intro to neonatology Flashcards
- Be familiar with the physiological differences of neonates and changes that occur after birth
- Understand the common problems associated with being small for dates
.
CVS starts developing in what week
End of 3rd week
Foetal circulation
- function of ductus venosus
- function of foramen ovale
- function of ductus arteriosus
DV - shunts blood from umbilical vein directly to IVC, so allowing OXYGENATED blood from placenta to bypass the liver
FO - a hole in the septum between the 2 atria shunting blood from left atrium to right atrium
DA - shunts blood from the pulp artery to the descending aorta, allowing blood to bypass lungs (so carries LOW OXYGENATED BLOOD)
What happens to the following after birth
- ductus venosus
- foramen ovale
- ductus arteriosus
- umbilical arteries
DV - ligamentum venosum
FO - becomes fossa ovalis in RA
DA - becomes ligamentum arteriosum
Umbilical arteries - some becomes *MEDIAL umbilical ligament, some stays open as branch of internal iliac
*DON’T CONFUSE WITH MEDIAN UMBILICAL LIGAMENT = REMNANT OF EMBRYONIC URACHUS
Normal vital signs of full term newborn
- BP
- RR
- HR
BP - 70/44
RR - 30-60
HR - 120-160
–> bradycardia <100
How is a baby’s temp regulated
- in utero
- newborn
In-utero - relies on mum’s thermoregulation
Newborn - lack shivering thermogenesis so need metabolic source of heart instead = BROWN FAT (packed with mitochondria to burn energy when needed)
Heat is lost through what 4 processes
Radiation
Convection
Evaporation
Conduction
How is newborn breathing investigated
NIV
- Blood gas
- -> PaCO2 = 5-6kPa
- -> PaO2 = 8-12 kPa
Invasive
- capnography
- flow volume loop
Physiological jaundice appears within how many days of birth and disappears within how many
2-3
7-10 for term and up to 21 for preemies
Why does physiological jaundice occur in babies
Babies have a high number of RBCs in their blood, which are broken down and replaced rapidly (HIGH CELL TURNOVER) so lots of bilirubin produced which is not removed from the body quick enough by the liver as it’s not fully developed yet
High concentrations of bilirubin in blood can cause an irreversible change in the brain called what
KERNICTERUS - just refers to high bilirubin levels crossing BBB and damaging brain
Neonatal jaundice only treated when it become *pathological (acute bilirubin encephalopathy)
What’s the treatment? (2)
*usually is just physiological
Exchange transfusion - removing their blood and giving new blood
+ phototherapy
Why is phototherapy given to babies with pathological jaundice?
Blue light converts bilirubin to water soluble form and increases oxidation of bilirubin so decreasing blood conc. of it
Full term baby is able to maintain fluid balance
Weight loss of up to 10% is normal in newborns
In what ways is fluid lost?
Shift from interstitial to intravascular
Diuresis - peeing it out
It’s normal not to pass urine for the first … hours
24
Why is fluid balance abnormal in premature babies?
Less fat
Increased kidney loss
-reduced Na reabsorption and reduced ability to concentrate or dilute urine
Increased insensible water loss
-e.g. sweating, breathing
Newborns get normal physiological anaemia
They’re born with Hb 15-20g/L but this falls when and to how much?
But increases in what week?
Week 10 - Hb 11
Week 20 - to Hb 12
Premature babies are very susceptible to anaemia - why?
Low erythropoiesis
Infection
Getting blood withdrawn (for tests)
- Establish neonatal definitions.
- Describe routine management and care of the premature baby.
- Understand short and long term complications of being born prematurely.
- Understand the potential outcomes of extreme premature birth
.
Low birth weight =
Very low birth weight =
Extremely low birth weight =
<2500g
<1500g
<1000g
How many weeks
- preterm baby
- extremely preterm baby
-what is considered the youngest age viable for a premature baby
<37 weeks
<28 weeks
24 weeks
Maternal causes of babies being small for gestational age
Smoking
Pre-eclampsia - decreases perfusion of placenta
Carrying twins
Foetal causes of being small for gestational age
Chromosomal syndromes, e.g. down’s, edward’s
Congenital infection, e.g. CMV
Placental causes of being small for gestational age
Placental abruption
Short term complications for baby of being small for gestational age
Perinatal hypoxia Hypoglycaemia Hypothermia Polycythaemic, thrombocytopenia GI PROBLEMS - NEC, poor feeding ARDS
Long term complications for baby of being small for gestational age
Hypertension
Reduced growth
Obesity
IHD
Common short term complications of premature babies
RDS
Ventilation management and complications, e.g. pneumothorax
Biochemical disorders, e.g. acidosis
Temperature control
Nutrition and fluid management
Infection, e.g. necrotising enteric colitis (NEC)
Brain haemorrhage (IVH)
Circulatory issues (e.g. PDA - persistent ductus arteriosus)
Jaundice
A short term complication of premature (preterm) babies is RESPIRATORY DISTRESS SYNDROME
How can this be prevented before birth?
What is the treatment for the newborn?
Steroids (dexamethasone) to the mother
Surfactant ASAP
NIV
A mild short term complication of premature babies is apnoea/irregular breathing
How is this treated? (2)
Caffeine
NIV (CPAP)
A short term complication of preterm babies is IVH (intraventricular haemorrhage)
How can this be prevented before birth?
What is the treatment for the newborn?
Steroids (dexamethasone) for mother
Supportive care mainly
-SYMPTOMATIC relief for newborn
A short term complication of preterm babies is IVH
Long term complications of premature babies
Retinopathy of Prematurity (ROP)
Periventricular leukomalacia (PVL)
Post haemorrhagic hydrocephalus (PHH)
Chronic lung disease/ Broncho Pulmonary Dysplasia (BPD)
Developmental delay and cerebral palsy
Poor growth
Post haemorrhage hydrocephalus (PPH) is a long term complication in premature babies
It involves bleeding into the CSF which increases ICP and progressively DILATES VENTRICLES; usually follows IVH
What is the treatment of the newborn?
VP shunt
Patent ductus arteriosus is a short term complication of premature babies
What does it lead to?
Usually connects pulm artery to aorta so blood can bypass lungs but persistent patency can cause blood from the aorta to leak back to pulm circulation –> increasing pulm pressure –> lung oedema
–> also stealing from systemic circulation –> systemic ischaemia
Complications of patent ductus arteriosus
Respiratory distress syndrome
Hypoperfusion of end organs, e.g. necrotising enterocolitis (from GI ischaemia)
CHF long term
Necrotising enterocolitis is a short term complication in premature babies
It involves ischaemia of the bowel –> necrosis
What is the treatment?
Supportive
- STOPPING MILK FEEDS to let bowel rest
- IV nutrition instead (not milk)
- Antibiotics - if infection
Surgical
- gastric decompression
- abdominal drain
- laparatomy - to resect dead bowel
Potential outcomes of EXTREME PREMATURITY
Death
Normal
Physical or learning disability
